The invention relates to a converter plant including a tiltable converter surrounded by a casing to whose ceiling a principal discharge conduit for conducting away refining gases is connected, part of which casing is fastened to a charging arrangement and is displaceable with the same.
When a converter of a steel-making plant is in operation, flue gases escape from the converter mouth during refining, which gases mainly consist of carbon oxides and FeO-particles carried away therewith. These flue gases, which are also referred to as principal emissions, have to be cleaned, and the energy contained therein possibly has to be regained before being released into the atmosphere. Also when charging a converter with scrap and pig iron and tapping the molten steel into the casting ladle, intensive smoke will sometimes develop, which smoke is referred to as secondary emissions. An even greater nuisance in terms of the development of smoke and fume is caused in steel-making plants with bottom-blowing converters, e.g. when carrying out the OBM-process, since the introduction of auxiliary agents into the bottom valves of such converters leads to spatters in the form of showers of sparks.
In recent times and in highly developed industrial countries, strict regulations with respect to the prevention and reduction of the emissions, and also regulations for increasing the safety of the operating personnel, have been introduced. The known arrangements for conducting away converter flue gases do not meet these high demands.
The known arrangements for conducting away flue gases comprise hoods surrounding the converter mouth and connected to discharge conduits that can seize reliably neither the principal emissions nor the secondary emissions. Also an arrangement has become known (German Offenlegungsschrift No. 22 33 443) in which a converter of a steel-making plant is enclosed on all sides with only a little more space than is needed for a tilting movement of the converter. Charging of the converter is effected through a lateral opening into which the lip of the charging container or a charging channel is introduceable. During charging, the charging opening remains open, and therefore it is not possible to prevent noxious substances of the secondary emissions to escape through the charging opening, thereby reaching the atmosphere and endangering safety. This danger exists particularly with OBM-converters during the admittance of gases to the bottom valves.
Furthermore, a plant is known (Austrian patent No. 329,895) in which a stationary melting furnace, in particular an electro-arc furnace is surrounded by a casing, wherein a crane can be passed over the furnace. Plates are fastened to the crane at distances which alternately close a casing opening during movement in and out by the crane. Such arrangements are, however, not suited for converter plants in which large amounts of flue gases emerge during the refining phase. Efficient converter plants have to include two discharge conduits, i.e. one for the primary and one for the secondary emissions.